Can the partitions in a custom internal partition plastic box be fitted later?

Answer: Yes, at two costs: a 0.3 mm slot gap lets the board move, and the slot floor cracks first in a drop.

Do more cells always cost more?

Answer: No. Extra cells add angled pins at 800 to 1500 RMB each; price barely moves. A cell under 40 mm wide forces a slider.

Is a 1.8 mm partition strong enough?

Answer: Up to 120 mm wide and 3 kg per cell, yes. Past that it bows, and 1 mm of bow removes 2 mm of clearance.

How many tiers should be published?

Answer: One above real storage height, with conditions attached — 72 hours, 38 degrees Celsius, 2 mm deflection.

How many sample rounds are needed?

Answer: Two. The first proves cavity and cells, the second proves wall and load. Then the grid freezes.

Custom Internal Partition Plastic Box Specs: Size, Wall and Load

Quick answer: A custom internal partition plastic box is fixed by four coupled numbers: cavity clearance, cell size, partition thickness and per-cell load. Subtract partition thickness from the cavity to get cell width, then size the wall by cell width — 1.8 mm to 120 mm, 2.2 mm to 180 mm, 2.6 mm above.

How a Custom Internal Partition Plastic Box Spec Is Layered
Cavity Size and Cell Geometry Maths
Partition Wall Thickness and Rib Layout
Per-Cell Load and Stacking Limits
Hinge, Handle and Machine Tonnage Matching
FAQ

1. How a Custom Internal Partition Plastic Box Spec Is Layered

A custom internal partition plastic box is never defined by one dimension table: the envelope decides pallet fit, the grid decides whether contents drop in, and wall thickness decides whether it holds shape.

Work backwards from the pallet: 600 x 400 x 230 mm on a 1200 x 1000 mm pallet, or 530 x 360 x 200 mm on a 350 mm shelf, with 8 mm feet keeping load on the lid. Cavity and cell stay separate lines, since a cell is one wall thickness narrower.

Layer	Fixes	Typical value
Envelope	Length, width, height	600 x 400 x 230 mm
Cavity	Clearance, draft	2 mm per side
Grid	Cells, count	4, 6 or 9
Wall	Side, base, partition	2.5 / 3.0 / 2.2 mm

2. Cavity Size and Cell Geometry Maths

Cell width is subtracted, not divided. A 542 mm cavity split four ways by 2.0 mm partitions gives (542 - 3 x 2.0) / 4, or 134 mm per cell.

Custom internal partition plastic box: black foam insert in a yellow case, two recesses cut into the foam, edges tight to the wall

Shrinkage runs 1.5 to 2.0 percent for PP and 0.4 to 0.6 for ABS; at 0.7 percent a 600 mm length needs 4 mm of allowance. Cells must agree within 1.0 mm on diagonal, and 1 degree of draft adds 3.5 mm over a 200 mm depth.

3. Partition Wall Thickness and Rib Layout

A moulded-in partition forms in the same shot at 1.8 to 2.6 mm; a drop-in board is slotted at 2.5 to 3.0 mm in a slot 0.3 mm wider. Which one a custom internal partition plastic box uses depends on cell width, not price.

Ribs add stiffness: 1.0 mm thick, 5 mm tall, 45 mm pitch, root fillets at R1.5 or more. Cells deeper than 60 mm need angled pins at 3 to 5 degrees; past 120 mm with cells under 40 mm, only a slider works.

Partition	Thickness	Max cell width	Load
Moulded thin	1.8 mm	120 mm	3 kg
Moulded standard	2.2 mm	180 mm	4 kg
Moulded heavy	2.6 mm	240 mm	6 kg
Drop-in board	2.5 to 3.0 mm	300 mm	6 kg

4. Per-Cell Load and Stacking Limits

Per-cell load comes from partition thickness at 2.2 kg per mm: a 2.2 mm partition works out at 4.8 kg, published as 4 kg to allow for ageing. The figure is static, not an impact rating.

Custom internal partition plastic box: yellow case open, grey foam cut with recesses for an anemometer, probe, cable and meter, two yellow latches

Whole-box capacity is not cell load times count. Partitions carry weight and the base passes stacking force upward, so the figure is cell load times count times 0.8: six cells at 4 kg rate 19.2 kg. Stack testing runs one tier above the intended height — 72 hours at 38 degrees Celsius, base deflection under 2 mm.

5. Hinge, Handle and Machine Tonnage Matching

Above 12 kg loaded, a custom internal partition plastic box needs a twin-axis hinge with a metal pin; plastic wears oval in three months. Opening force sits at 25 to 45 N.

Tonnage follows projected area at 0.45 tonnes per square centimetre: a 600 x 400 mm lid projects 2400 square centimetres, so it needs 1080 tonnes. A 2.5 mm wall cools for 32 seconds in a 68 second cycle.

Envelope	Press	Cycle
400 x 300 mm	550 t	48 s
530 x 360 mm	850 t	58 s
600 x 400 mm	1000 t	68 s

Conclusion

Specifying a custom internal partition plastic box is subtraction: envelope minus wall gives cavity, cavity minus partition gives cell, cell times a factor gives load. Put all four on one drawing and two sample rounds settle it, so a custom internal partition plastic box keeps size, wall and load in agreement.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.